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| author | Jan Kara <jack@suse.cz> | 2013-09-11 14:22:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:57:55 -0700 |
| commit | 47df3ddedd22c3f8e68aff831edb7921937674a2 (patch) | |
| tree | 3a8b82782ef6c90e7974063b642e5bbab04fd55e /mm/page_alloc.c | |
| parent | 7cb2ef56e6a8b7b368b2e883a0a47d02fed66911 (diff) | |
| download | lwn-47df3ddedd22c3f8e68aff831edb7921937674a2.tar.gz lwn-47df3ddedd22c3f8e68aff831edb7921937674a2.zip | |
writeback: fix occasional slow sync(1)
In case when system contains no dirty pages, wakeup_flusher_threads() will
submit WB_SYNC_NONE writeback for 0 pages so wb_writeback() exits
immediately without doing anything, even though there are dirty inodes in
the system. Thus sync(1) will write all the dirty inodes from a
WB_SYNC_ALL writeback pass which is slow.
Fix the problem by using get_nr_dirty_pages() in wakeup_flusher_threads()
instead of calculating number of dirty pages manually. That function also
takes number of dirty inodes into account.
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Paul Taysom <taysom@chromium.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
0 files changed, 0 insertions, 0 deletions